In order to increase the available interior space of recreational vehicles or trailers, slide-out rooms or sections can be made integral with the structure of the vehicle or trailer. During transit, these rooms can be retracted and stored in the interior of the vehicle or trailer, with the exterior wall of the slide-out room approximately flush with the exterior of the vehicle or trailer. To use the slide-out room, the vehicle is first parked and leveled. The slide-out room is then slid outward from the vehicle, increasing the interior space of the vehicle.
A number of motive devices are currently used to extend and retract slide-out rooms. These devices may be hydraulic, pneumatic, electric, simple gearing mechanisms, sheave and pulley arrangements or various combinations thereof. One common type of mechanism used in the prior art for extending or expanding trailer bodies is a motor actuated cable and sheave mechanism such as disclosed in U.S. Pat. No. 5,332,276 issued Jul. 26, 1994 to Blodgett, Jr. Another arrangement for moving a slidable trailer room is a worm gear system driven by an electric motor as set forth in U.S. Pat. No. 5,237,782 issued Aug. 24, 1993 to Cooper. Another slide-out mechanism design which employs a motor actuated rack and pinion drive is shown in U.S. Pat. No. 5,333,420 issued Aug. 2, 1994 to Eden.
While some of the prior art trailer extension and expansion devices have yielded satisfactory results, most have demonstrated a number of shortcomings. For example, in the cable and sheave systems, there is the problem of the cables stretching, causing slippage in the sheave and eventual jamming or binding of the structural members which support the slide-out section. In an attempt to rectify this, some cable and sheave systems require a compression spring mechanism which adds to the overall installation and maintenance costs of this particular type of system. Arrangements employing worm gear operating mechanisms have proven to be unreliable and noisy and are subject to the same types of binding as aforedescribed. In the case of rack and pinion sliding mechanisms, gear assemblies had to be coordinated with corresponding gear racks on each of the sides of the expandable sections. Any misalignment between any of the racks and pinions leads to synchronism problems which can result in the slide-out section becoming skewed or binding during the transit sliding action.
It remains desirable to provide an operating mechanism for a slide-out section of a trailer which is sturdy, reliable, easy, and quietly operated. It is also desirable to provide an operating mechanism which provides smooth, uniform and responsive movement as well as positive locking of a slide-out section. It is also within the purview of the invention to contemplate various drive options for moving the slide-out section back and forth.